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192 April 19 7 B. voLKMAR TIMER FOR INTERNAL COMBUSTION ENGINES FiledMay 17. 1922 INV NroR n f J, ,wAnpRNEt Patented Apr. 19, 1927.

BERNHARD VOLKMAR, OF NEW YORK, N. Y.

TIMER FOR INTERNAL-COMBUSTION ENGINES.

Application filed May 17,

My invention relates to improvements in the type of timer described inmy co-pending application Serial No. 429,315, which timer consistsspecifically of a hub having a radially extending housing containingtherein a cylindrical roller brush thrust toward the commutator by aspring, and a bearing plate between the spring and the roller, hardenedwear surfaces being provided for the portion of the housing with whichthe roller contacts.

Timers for internal combustion engines are subjected to severe wear byreason of their high speeds and prolonged use, eX- perience havingdemonstrated that in the type of timer described in my aforesaidapplication, the life of the timer is somewhat shortened because of wearupon the outer surface of the brush as well as upon the wall of thehousing with which it engages.

While in actual practice such timers have given satisfactory results,and their use has extended into the thousands, I have by my presentinvention provided a structure wherein the wear upon the roller brushwill be so distributed as to materially increase its life, and of thebrush unit in its entirety without interfering with that reliability ofaction resulting from the tendency of the cylindrical roller to becontinuously engaged with the commutator ring under the combined actionof the spring within the housing and centrifugal force while the timeris in operation.

I secure the desired results by mounting the roller bearing upon abearing pin or shaft which is slidably mounted in the Walls of thehousing so as to be capable of having movement towards the commutatorwith the roller until considerable wear has occurred upon the. co-actingbearing surfaces of the roller and its shaft. Until such wear occurs,the shaft will hold said roller out of engaging relation with the wearplate cai ried by the housing, thus limiting the initial wear upon theroller to that resulting from the engagement with the commutator ring,but when looseness occurs between said roller and its bearing pin orshaft, permitting said roller to engage said wear plate so as to causewear thereafter to occur only upon the periphery of the roller until theroller again engages its shaft. In this manner, which causes a shiftingof the axis of rotation of tbc roller as a result of Wcar be- 1922.Serial N0. 561,601.

tween it and its bearing pin and results in the alternate bearing of theroller upon its shaft and upon the wall of the housing, I am enabled tomore than double the life of the timer.

The invention consists primarily in a timer for internal combustionengines embodying therein the combination with a commutator ring havinga sequence of spaced contacts and vsubstantially Hush interposedinsulated sections presented inwardly of said ring, of a brush adaptedto be rotated in synchronism with the engine shaft, consisting of a hub,a'radially extending housing having parallel side walls with oppositelydisposed elongated openings therein extending radially of said hub, abearing shaft slidably mounted in said openings, a substantiallycylindrical contact roller rotatably mounted Vupon said shaft andslidably mounted Vwithin said housing with its sides -in substantialengagement with said side walls, whereby continued wear will bedistributed between said roller and said shaft, and between theperimeter of said roller and the wall of said housing, a spring in saidhousing having a normal tendency to thrust said roller through andbeyond the open end of said housing, and a wear plate slidably mountedwithin said housing below said shaft and positioned between said sprinand said roller, whereby scoring of the sur ace of said roller by saidspring is prevented, said spring being held under tension by theengagement of said roller with said commutator ring; and in such othernovel featuresA of construction and combination of parts as arehereinafter set forth and described, and more particularly pointed outin the claims hereto appended.

Referring to the drawings,

Fig. l is an elevation of a comniutator ring and a brush embodying myinvention associated therewith, taken on the line l--l of Fig. 3, aportion of the housing of the brush being broken away;

Fig. 2 is a detail vertical section through the brush;

Fig. 3 is a section on the line 3--3 of Fig. 1; and

Fig. 4 is an exploded view of the roller and its shaft.

Like letters refer to like parts throughout the several views.

means of'a suitable lever system connected` witlitlic,l ug c to advanceor, retard` the spaxlt. 'lfhi's eneral' coastiiuction andf arrangementisoldlandlwellfltnown in the. art and no claim of invention is-inadethereto.

Associated with said'. cnmmutat'or is a huish-mechanism which is rot-tedinsyiichronisnrwiththe engine sha/ft, prefenabl'y b' beingniountcd uponlan extension thereo which is indicated at. d in the drawings.

'Illijs brush coii'ipris'es a hub c having aY 'suitablezslbt' thereinada ted-:to co-operate withiapinfiupon the sha tgdjso as to iacilr.itgite' the mounting and removingofA thel brush with-,relationto theshaft to cause it teirotate therewith.

The habe is provided with Vaiadially, ex.-

texided; housing (1,. the open top of" which terminates adjacent thecoinmutaitorf ring,

siicient clemence: being aiorded to avoid: possiblecontact of the en .dofthe liousingT \i'i th said` coniinutator. i' The, chamber of'thehousiiigig is metan-- guiar in section and the; opposite.Y sides thereofare provided 'withv rectilineally arranged slots. gf`g2 extendingradially offthe hub" e and openingontWardly ofsaid hjousing-1at one endtliereof'toffacilitate the"l assemblingzotlietim'cr. The lchamber of:the housing. g is so formed' to accomm0 date a ,.siibsta nti allycylindricahcontact roller" h which is .i'otatahllr inouiited`-`upon ahear ing pin. or shaft It",- the ends of which' are; slidtlbl' mountedAin the slots g;"'g-- so as to permit. u free.. movement of' saidshat:inclthe roller In radially oflthe huh e with ef said roller to an axisparallel to that .of' said hub, permitting the i-ollerj'to.l 'recedewithin the housing ti). lit/'the brush' tothe commutatorring, andcompensate for irieg-'- ularities in. the surface of'saidiifiig-Co-0Heitf ating withl said roller, and*l distributing;icontinued wear between the co-operating bearing surface o'said rollerand said shaft., andbetweentheperimeter of said roller and' thewallfof'said housing.

It is to., he observed that the initial rotation of the roller i,will'he about' its shaft' lit but that as weer occurs upon these parts,

the zi-xis of rotation of' the roller may shift :is :l result of tiu:iuguiar thrust upon the the. objects' of' limiting the. rotarymovement;`

"roll'er, so that ultimately said roller will engage with thercaii--walll of the4 housing i inthe-dreetion oinovement thereof? XV henwear occurs upon said housing the roller williagraimbeanuponz-the shaft.'i aione, until 70 wear upon said shaft or upon the portion othe,mlleiibearing thereon, will again permit engagement of the perimeter ofthe rollerwitl'r tlle'llousing, this alternate wear of. parts continuinguntil the roller is` no I5 longer t for service. I pi'efei'abljj use :ibearing 'shaft' h having flattened. ends as. shown atllg so as 17o-limitthe movement of' this shatwithintlie-slots f/-g? to a reciproca torymovement toward' and' fronr the coni.- s" inutaoi' ring,"

lit'hiril t-liehousing g is a coi1ed"sprng i which is normally heldunder tension by the roller h as a; result of its movementinl wardly-osaid housing, a wear platezj being interposed between said spring andthe' perimetci'lofsaid' roller to avoid abrasion othe contact surface ofsaidroller from the end of' the teinpered'spring:

The spring i' has siilicient' strength to- 90' ii'iaintain` the rolleri'n' constant, Acontinuous engagement-with' the commutator. ri'n', thuspreventing jers or'jplts occasioned the 1 assnge 'ot`'a1reliile. overrough' roads, 'fiom' caiisinfr' the roller to, recede iom lthe ifing 95'to prevent the' closing of, or interrupt the circuit, :is `determined'b'y. the. relation ofthe contact seginentsl', 2; 3 or 4; to the pistons'oztlie' different c.Ylr'idis to be fired by th? closiiigfoftlte circuit'through' -said contacts, lo I 'he' roller. h A.aiifdj shift h" po'sssso .little weiglitiii'. ,themselves tlibtliey. will? 'have littletendencip more ugainsttlle, tQnSDn fessi a.' resul-voisins -i'plis ltlie. v'eliiele", the"tei'nilegicy; toward :dis-' m5 Plldmt of therellerinivardi Q`jf tl'ie li'oussJ i'i'igl; ainst'tle' tension, f1'sand`springby: such* )olts a'ntl jai-s being f iitllei -mini inized'by. the actionof centri'igiilj'iice l The liousifng'-g for ci'ivenience of-mml-sf'tiir been.' mede.' sift' metal', m11 since war'willlioclcnr upon thelreni wall.o this liamber'effteij` the 'timer-Alias been, i'u. use -.fora' iconsi'deitihle time as heretofore, stated,1 I'piiovidev n ivzearplatte in the, foi'in olf' au'lslinped' spring k. adapted to, receii'ebetween itsfajrmstle spring weer plate] and' roller; hl with ,its shaft117 which will; reduce wai: at tliislpoiiit. and: wilkalsofaclitate the,a, ssemlilixig` of.' the tuner, By. slightlyl crimping tlie'eilids ofthearms of, this' spiinginwaidly as. shown; saidirolle'r. :in djts sli'uft.will beheld.' .against displacement-j infthe assembled stmictuize,these. i'n-. turned edges not ntenfei'iiig, with the free rotationfftlie roller, sin-:o ander normal. conditions the roller, will' bepressed within. the chamber suiiibiently, to. ensure contacto'f. theperimeten thereoffwith one arm of.'tlie spring Z: well below saidcrimped portion.

liii

The operation of the herein described timer is substantially as followsIn assembling the brush in a timer, the casing a is removed and the hube mounted upon the shaft cl by means of the pin f, said housing and itscommutator ring being then replaced, the roller h being depressedagainst the tension of the spring z' so as to bring this roller withinand in engagement with the operative surface of said ring, and with theshaft h', which shaft will have movement in the slots g'-g' with thedepression of said roller against the tension of the spring i. A looserunning fit is provided between the roller h and its shaft h', andbetween the ends of the roller and the side walls of the housing, thusavoiding any necessity forllubrication and ensuring against thedevelopment of an oil tilm upon the contacts l, 2, 3 and 4.

lVhen the spring i is tensioned in the manner above described, it willforce the roller L and its Shaft I. outwardly with suiiicient force tomaintain said roller in constant engagement with the commutator ring soas to ensure accuracy in the timing of the ignition of the explosivecharge in the respective engine cylinders, and maintain the circuitclosed for a period determined by the length of each contact segment. Ihave found in actual practice that severe jarring of the vehicle willhave no tendency to causethe disengagement of said roller from thecommutator ring and that a roughened surface of said ring will notinterfere in any way with the tnnely making and maintenance of a perfectcontact. In fact I have found, when using a brush made in accordancewith my invention, with a badly corrugated commutator ring, that therewas not only no loss of, nor interruption in, the contact, but that witha continued running of the engine, the ring will be brought to a truesmooth surface.

The constant thrust of the spring z' and the constant engagement of thewear plate j with the roller h as a result of such thrust,

ensures continuity in the ground connection through the brush and theshaft nl, there being no possibility or likelihood of the partial orcomplete insulation of these parts v reason of the presence of an oiltlm thereon. Furthermore, the constant cngagement of the roller withsaid wear plate and with the shaft h or with the wear plate k ensuresbright and clean contact areas between the roller and the conductingmedium for leading the current to said shaft d.

As heretofore stated, the initial wear in the operation of the timerwill be between the roller h and its shaft h. the subsequent wear beingalternately upon the wear plate l: and upon said shaft, and upon theportions of the roller engaging therewith, thus not. only distributingthe wear between two areas upon said roller and between said shaft andsaid wear plate, but avoiding excessive wear as a result of a continuedfrictional engagement of the same portion of the roller with the sameopposed surface.

lVear upon the roller itself will he compensated for bythe action of thespring i and wear plate j thereon.

Aside from the added facility in assembling the timer and thedistribution of wear as described to prolong its life.l which conditionsresult from the use of the U- shaped spring k and the bearing sha-ft h',a timer embodying my invention has all of the desirable characteristicsof the timer of my aforesaid application.

It is not my intention to limit the invention to the precise details ofconstruction shown in the drawin it being apparent that such may bevaried without departing from the spirit and scope of the invention.

Having described the invention, what l claim as new and desire to haveprotected by Letters Patent, is

1. A. timer for internal combustion engines embodying thereinthe'combination with a commutator ring having a sequence of spacedcontacts and substantially flush interposed insulated "sectionspresented in'- wardly of said ring, of a brush adapted to be rotated insynchronism with the engine shaft, consisting of a hub, a radiallyextending housing having parallel' side walls with oppositely disposedelongated openings therein extending radially of said hub, a bearingshaft slidably mounted in said openings, a substantially cylindricalcontact roller rotatably mounted upon said shaft and slidably mountedwithin said housing with its sides in substantial engagement'with saidside walls. whereby continued wear will be distributed betweensaidroller and said shaft, and between the perimeter of said roller `andthe wall of said housing, a spring in said housing having a. normaltendency to thrust said roller through and beyond the openend of saidhousing, and a wear plate slidably mounted within said housing belowsaid shaft and positioned between said spring and said roller,wherebyscoring of the surface of said roller by said spring isprevented, said spring being held under tension by the engagement ofsaid roller with said commutator ring.

2. A timer for internal combustion engines embodying therein thecombination with a commutator ring having a sequence of spaced contactsand substantially flush interposed insulated sections 'presentedinwardly of said ring, of a brush adapted to be rotated in synchronismwith the engine shaft, consisting of a hub, a radially extending housinghaving parallel side walls with oppositely disposed elongated openingstherein! extending' radially of said hub, a

ings, a substantially cylindrical contact roller rotatablymounted=uponsaid shaft and '-slidably mounted within said housing with its sides insubstantialengagement with said side walls, whereby continued wear will.be distributed between said roller and said shaft, and between theperimeter of said roller and the wall ot said housing, a spring in saidhousing havingr a normal tendency to thrust said roller through andbeyond the open-- end' of said housing, awear plate slidablymountedwithin said housing below said shaft andf positioned between saidspring and said; roller, whereby scoring of .the sur face of said rollerby said spr-ing is prevented, saidspring being held undertension-bytheengagement of saidlroller with said commutatorring. and a wearpla-tein the forniof! a- Ushapedspring. adapted toreceive betweenits. armssaidspring, said. wear plate and said rollerwith its shaft 3.. A timerfor inter-nal combustion engines embodying therein. the eombinat-ionwith acommutator r-ing. having-asequence of. spaced contactsand-,substantially flush. in-- terposed. insulated sections presentedoppositelyf disposedelongated-. openings,

thereim extending radially of saidhub, a-

i"bear-ingsha-h slidably Amounted in said openings; a= substantiallycylindrical contact.

rollerrotatably. mounted-1 upon said shaft andslidably` mountedwithin.said housing' with its sides. insubstantialengagement with-said sidewalls,`whereby` continued wear. will: befd-istributed. betweensaidvrollerand*- saidishafgandfbetween.the perimeten of. said.

roller and thef wall ofz said.housi1ig,.a.spring,

in. saidhousing having a. normal.' tendency. to-thrust said.rollerthrough. andzbeyond. theo en-end.of saidhousingawearplate slid.--a ly mounted' within-said-honsing below-said sha-ft andpositionedbetween; saidspr-ing,

and' sa irl-.roller` .whereby Scor-ingE .ofthel surtaoe-of-'saiderollerby said.spring is prevent.- ed, Saidspringl heiligheid-undertensionhythe-engagement of said-roller with said-com@ mutnter ning,aud-.a-Wear plate in the formofi zu-U.sliapedl spring. adapted toreceive bctween its arms said spr-ing., said-wear plate and said'rolle-r. \\-'itl.1-its-shaft` .the-.ends of the arnisof. said.Llfshaped-springt being: crimped. toward. eachotherto facilitate theassem-- blingiofl the parts-01'."- the-br-ush. wtlrrelation. toeachother and--thebrush. withrelation to the commutatorring.

4i A, timer forl inter-nal combustion engines embodying therein thecombination. with a commutaton ring having a. sequence 5f ofspacedcontacts and substantially flush.

m-. wardlyof; saidring, of abr-ushadapted toA berotatedl in--synchronismwith. theengineinterposed insulated sections presented: inwardlyofsaidring, of. a brushadapted to be rotated: in synchronism@ withtheengine shaft, consisting ojzwhub; a radially extending' housingrhaving, parallel side wallswith oppositel'yE disposed elongated openingstherein extendingt radially of said hub, hav.- ing their ends openingoutwardly ofsaid housing, a bearing, shaft slidably mounted in saidopenings, a substantially. cylindrical Contact roller rotatably mountedupon'said shaft and slidahly mountedwithin said housing withits sides insubstantial engagement with. said side walls, whereby continued wearwill be distributed between. said roller and-fsaidshaft-,.andbetweentheperimeleu of saidrollerand the-wall ofsaidhousingaspring .insaid housinghaving: a normalv tendency ta thrust said roller. throughand beyond theopen endof. said housing, and awear plate slidably-mounbed within saidhousingg below said: sha-ft andpositioned between saidsspring and said:roller,.whereby scoring of the-surface of-said roller by said springisprevented, saidspring. being, held undertension-by the engagement ofsaidroller. with said commutaton ring. Y.

A timerforinternal. combustion. en.- gines embodying. therein f thecombination. with a. commutator ring. having a. sequence: of spacedcontacts andsubstantiallyflush. interposed insulated-sections presentedinfwardly of said ring-,.of a brush. adapted. to. he rotatedin:synchronisnLwit-hthe-engineshaft, consisting of'ahub,.aradiallyextend-.- ing housinghavino'. parallel-.side walls with.oppositely disposeda-elongated openings there` in extending radially ofsaid hub, haring-j their. ends openingfout-wardly: of. SaidA housing-,abearing shaft slidably mounted.. in

shaft and slidably mounted within said'.

housing with its sides in substantial engage--- ment with.A said sidewalls, wherebyA continued -wear will be distribntedbetween saidi roller.'and said shaft, and" between. tlie per-- inietcr` ofsaidrollen-and Athewall of'said' housing;` aV spring-in said. housinghaving a normaltendency. to. thrust said roller through and beyond the open end. ofsaid housing, a wear. plate slidabl'y mounted' within said housinghelfen: said shaft andpositioncd. between said'4 spring and. said`roller, whereby scoring of thesurface of' said. roller by said4 spning,is prevented, said spring being held. under tension by the engagenientof .said roller. with: said commutator ring, and a wear plate ih theform of: a U-shapcd: spring adapted to. receive betuccn. its arms saidspring, said wear plate and said rolle.r with its shaft,.tlie ends otthcarms of said U-sliaped' spring. being crimped toward cach othertofacilitate the assembling of the parts of the hrush with relation toeach other and the brush with relation to the commutator ring.

6. A timer for internal combustion engines embodying therein thecombination with a commutator ring having a sequence of spaced contactsand substantially flush interposed insulated sections presented inwardlyof said ring, of a brush adapted to be rotated in synchronism with theengine shaft, consisting of a hub, a radially eX- tending housing havingparallel side walls with oppositely disposed elongated openings thereinextending radially of said hub, having their ends opening outwardly ofsaid housing, a bearing shaft having flattened ends slidably mounted insaid openings whereby said shaft is limited to a reciproeatory movementtoward and from said ring, a substantially cylindrical Contact rollerrotat-ably mounted upon said shaft and slidably mounted within saidhousing with its sides in substantial engagement with said side walls,whereby continued wear will be distributed between said roller and saidshaft, and between the perimeter of said roller and the wall of saidhousing, a spring in said housing having a normal tendency to thrustsaid roller through and beyond the open end of said housing, and a wearplate slidably mounted within said housing below said shaft andpositioned between said spring and said roller, whereby scoring of thesurface of said roller by said spring is prevented, said spring beingheld under tension by the engagement of said roller with said commutatorring.

7. A timer for internal combustion engines embodying therein a brushconsisting of a hub adapted to be detaehably mounted upon a shaft, aradially extending housing having parallel side walls, there beingrectilineally arranged, elongated slots in said side walls respectively,ashaft mounted to have reeiprocatory movement in said slots, asubstantially cylindrical Contact roller rotatably mounted upon saidshaft and slidably mounted within said housing with its sides insubstantial engagement with said side walls, whereby continued wear willbe distributed between said roller and said shaft and between theperimeter of said roller and the wall of said housing, andelectrooonductive means yieldably thrustin said roller and its shaftoutwardly of sai hub, whereby said roller is permitted to rotate about avariable axis, and presents a wide Contact area to its cooperatingcommutator ring, said slidable shaft, the wall 0f said housing and saidelectro-conductive means.

In witness whereof I have hereunto affixed my signature this th da ofMay, 1922.

BERNHAR VOLKMAR.

